This invention relates to railway rolling stock and, more particularly, to a railway car center plate assembly.
The swivel connection of railway vehicles comprises a center plate assembly that is disposed between the car body or frame and the truck, allowing the truck to turn under the car about a centerpin. The center plate assembly conventionally used in railway cars comprises a body center plate attached to the underside of the body bolster and a truck center plate having the shape of a bowl and being secured to the top side of the truck bolster or cast integrally therewith. The body center plate secured to the body bolster and truck center plate secured to the truck bolster are provided with coaxial openings which receive a center pin therein to guide the engagement of the parts.
Under conditions in which railway cars are operated, breakage of the center plate assembly occurs much too frequently, especially in the larger cars currently coming into broad usage. During normal operations of railroad freight cars, the body center plate is the structural member which, together with the side bearings, transfers the railroad car load onto the truck. When in motion, the railroad car rocks from side to side. When the car rocks to one side a very small load-bearing surface, i.e., the peripheral edge of the body center plate, carries the weight of the car. The concentration of the car load on the body center plate plus the fact that it is intermittently applied and released has resulted in fatigue cracking of the center plate. Failure of the body center plate or the means of its attachment causes loss of car operating time while the center plate is being replaced or repaired. Accordingly, there has been a need for a railway car center plate assembly in which high-bearing stresses between the body center plate and truck center plate induced by the car rocking back and forth on the edges of the body center plate as it bears on one side bearing, then the other, are eliminated, thus assuring longer use. Further, there is a need for a center plate assembly that provides sufficient resistance to rotation of the truck to reduce the tendency of the truck to oscillate about the center plate, a condition known as "hunting".